863
FXUS66 KMTR 060001
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
501 PM PDT Sun Oct 5 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 203 PM PDT Sun Oct 5 2025

 - Warmer and drier conditions through midweek, with moderate
   offshore wind expected through Tuesday in the higher elevations

 - Unsettled weather returns late in the upcoming week

&&

.SHORT TERM...
Issued at 203 PM PDT Sun Oct 5 2025
(This evening through Monday)

Mostly clear sky conditions have returned to the region this
afternoon with temperatures forecast to peak in the 60s near the
immediate coast, lower 70s just inland away from the coast, and the
low 70s to lower 80s across the interior. This is a result of the
offshore flow in the higher elevations and building high pressure
over the eastern Pacific. However, troughing persist across the
Intermountain West with a cut-off low expected to develop overnight
just west of the Bay Area.

Low clouds and/or patchy fog are forecast to return back to the
coast and coastal adjacent inland valleys as the marine layer will
likely compress to around 1,000 feet in depth. The aforementioned
cut-off low will aid in increased offshore winds in the higher
elevations overnight and into Monday morning, being the strongest
over the North Bay and East Bay. Thus, the strength off the offshore
flow may limit low clouds and fog potential tonight and into Monday
morning.

Temperatures will warm into the upper 60s to lower 80s inland way
from the immediate coast with upper 80s across the interior on
Monday afternoon.

&&

.LONG TERM...
Issued at 203 PM PDT Sun Oct 5 2025
(Monday night through next Saturday)

Warm conditions will persist into Tuesday afternoon (similar to
those on Monday), yet onshore flow is expected to cool temperatures
near the coast. By Wednesday, onshore winds will return to much of
the region and cool temperatures to near seasonal averages.

There remains much uncertainty from Thursday and into the upcoming
weekend. There is fairly decent confidence that temperatures will
cool in response to an upper level through approaching and/or moving
inland over the Pacific Northwest. However, the confidence of
receiving rainfall remains the big question beginning Friday. The
greatest potential of seeing any rainfall will be over the North Bay
and in the Santa Cruz Mountains as a cold front moves through the
region.

From the previous forecaster: "The biggest question in the forecast
is if this moisture will reach the Bay Area before the cold front
arrives and stops its forward progress. If it does, the front will
have a very juicy atmosphere to lift, potentially bringing up to an
inch of rain to parts of the Bay Area. If it doesn`t, the offshore
winds all week will leave a drier than normal air mass, severely
limiting rain potential. To demonstrate the uncertainty, the NBM 72
hour precipitation spread (10th-90th percentile) paints a stark
contrast. The wet scenario would bring 1.7" of rain to NW Sonoma
County through the weekend, while the dry scenario wouldn`t bring a
drop. Those outcomes are both equally likely at the moment, so don`t
put too much faith in the forecast details. All we can say now is
the next chance for rain arrives late next week, but we can`t yet
say how much will fall."

&&

.AVIATION...
(00Z TAFS)
Issued at 501 PM PDT Sun Oct 5 2025

It`s VFR except along the immediate coastline satellite imagery
and surface observations show a few areas of low clouds /IFR/. The
WMC-SFO pressure gradient is currently 7.0 mb and forecast to
increase to near 10 mb tonight and Monday morning. Surface winds
are a mix of onshore and offshore, however overnight to Monday
morning offshore winds are forecast. Offshore winds, a compressing
marine layer under thermal ridging aloft support near high confidence
VFR forecast for the 00z TAFs. KHAF temporary IFR 01z-03z this
evening otherwise VFR.

Vicinity of SFO...VFR. West to northwest wind 10 to 15 knots
through mid evening trending toward light offshore wind tonight
and Monday morning. Northwest to west wind 5 to 10 knots Monday
afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Recent high resolution model forecasts
indicate a surface eddy circulation developing over the Monterey Bay.
Low clouds temporarily spin up with the circulation over the Monterey
Bay otherwise the circulation should precluded low clouds /IFR/ from
reaching the terminals through the evening. Offshore winds support
drier conditions tonight and Monday further supporting VFR at the
terminals. Surface winds will remain onshore to about mid to late
evening then shift to light offshore/cooler air drainage winds tonight
and Monday morning. Onshore winds redevelop Monday afternoon.

&&

.MARINE...
(Tonight through next Friday)
Issued at 441 PM PDT Sun Oct 5 2025

A weakening weather pattern over the waters is allowing for winds
and resultant seas to continue to decline. Look for light to
moderate winds and generally low seas for the next couple days.
Locally gusty winds and steep seas are possible around prominent
points and headlands.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...BFG

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea